The present invention concerns an X-ray tomography device adapted to petrophysics application, such as to study the flow of fluids into a porous medium. For example, the aim is to study the multiphase flow of a mix of two or three fluids inside a porous medium: a mix of any two of water, gas and oil or the three of them.
The known X-ray tomography systems are adapted to study the morphology of rock pores, to identify the minerals comprised into the rock sample (the porous medium) or the topology of various fluid phases present in the rock sample under static (ie non flowing) conditions.
Because of the 3D image reconstruction process included in these devices, the acquired images taken by a photon detector embrace the entire cell to have as much information as possible according to a spatial point of view.
In case, the region of interest is a small part of the cell, the 2D images acquired by the photon detector and the 3D tomography images calculated after reconstruction have a limited number of useful pixels.
Therefore, other known methods require stitching a lot of radiographies, and to reconstruct more data and to work on very large images for the 3D image treatment. These methods are acquisition time and calculation time consuming.